Positioning apparatus, including a first object and a second object, are known in lithographic apparatuses wherein the first object is part of a long stroke module and the second object is part of a short stroke module. The concept of the cooperation of the combination of a long stroke and a short stroke concept is a well known machine layout for a lithographic apparatus. Hereby, the long stroke module is responsible for a movement over a long stroke with a limited accuracy and the short stroke module object is able to move over a smaller stroke with a higher position accuracy. The short stroke module is then connected with the long stroke module via a flexible transportation line for transportation of for example electricity, fluids, vacuum applications, et cetera. A specific example is that the short stroke is provided with water via the flexible transportation line.
In the known positioning apparatus, the stiffness, damping and mass properties of the flexible transportation line act as a static and dynamic disturbance force between the first object and the second object. If the mass of the flexible transportation line is connected with a too low stiffness, a low natural frequency of the flexible transportation line may cause undesired disturbance forces due to the free moving mass of the flexible transportation line. Increasing the natural frequency of the flexible transportation line by increasing the stiffness of the flexible transportation line raises the direct coupling between the objects. The dynamic disturbance effects may result in position errors of the first object and the second object. Accordingly and as a consequence, these position errors may result in undesired imaging problems and/or overlay errors of the lithographic apparatus.